Gamma interferon is a protein produced by activated helper T cells which manifests antiviral, antiproliferative and immunomodulatory activities. The antiviral and antiproliferative activities of gamma interferon are largely suppressive, while the immunomodulatory activity is primarily expressed through stimulation of a variety of immune functions, although the inhibition of immune function is also known to occur.
Although the mechanism by which gamma interferon exerts its effects on cells is not understood, it is known that it binds to specific cellular receptors [Langer et al, Immunology Today 9:393 (1988)]. Aguet et al. [Cell 55:273 (1988)]have cloned and sequenced a gene for a gamma interferon receptor. The molecular weight of the encoded protein deduced from the sequence is consistent with the molecular weight of a gamma interferon receptor recently isolated from human placenta [Calderon et al., Proc. Natl. Acad. Sci. USA 85:4837 (1988)].
Gamma interferon is believed to be involved in autoimmune disease. Elevated levels of gamma interferon are also believed to stimulate macrophages that erroneously digest myelin in the brain and spinal cord of multiple sclerosis (MS) sufferers.
Because gamma interferon acts at specific cellular receptors and is implicated in autoimmune disease and MS, agents which could inhibit the binding of such interferon to its cellular receptors would be useful therapeutically.